A Synthetic Coal Was Made from a Furfuryl Alcohol Polymer with Appropriate Amounts of Sodium, Sulphur and Silica to Duplicate the Characteristics of a Low Rank Coal. the Synthetic Coal Was Burned in a Laminar Flow (Drop-Tube) Furnace at 900, 1100, 1300 and 1500 °C. the Resulting Fly Ash Particles Were Quickly Quenched, Collected and Analysed using a Scanning Electron Microscope to Determine Size and Composition. Below 1100 °C, Fly Ash Formation Was Dominated by Coalescence of the Mineral Matter in the Burning Particle to Form Close to One Fly Ash Particle Per Original Coal Particle. at Higher Temperatures, Fly Ash Formation Was Dominated by Fragmentation of the Coal/char Particle Followed by Coalescence within the Resulting Fragments. at the Lower Temperatures, Submicrometre Sodium Sulphate Particles Were Found Adhered to the Larger Sodium-Rich Silicate Particles. at Higher Temperatures, the Abundance and Size of the Sodium Sulphate Particles Decreased. © 1992.